i just got this Uniden BCD536HP for my chrismastmas and i have a stock antenna on it and im looking to get an roof top antenna which is the best one to get looking to spend 100 to 200 can some one help and help what the cables to
- Status
- Joined
- Apr 25, 2011
- Messages
- 1,403
Depends a lot on what exactly you're listening to. What frequencies are you interested in?
mmckenna
I ♥ Ø
$200 is a pretty good budget. Thanks for not saying your budget was $50 and then expecting the "best" antenna.
Start of by installing the highest grade coaxial cable you can afford. Unless it's a very short run from your antenna to your radio, you'd want to start with something like Times Microwave LMR-400 with the proper connector to match your antenna.
At the radio end, do NOT try to connect LMR-400 directly to your minty fresh scanner. Trying to connect stiff cable like LMR-400 directly to the antenna connector will quickly damage something, usually that minty smelling radio.
Invest in a short jumper from the LMR-400 to the scanner. This should be a lightweight and highly flexible cable with the proper connectors installed. Don't use adapters if you can afford it.
Another good option for coax is to use RG-6. You can find this at Home Depot. While it is a "TV" cable designed for a 75Ω system, it'll work just fine for a scanner.
If you ever plan on getting your amateur radio license, do yourself the favor of getting the LMR-400, it'll be a better choice if you plan on doing any transmitting.
Either way, one of those would work fine.
Lightning protection should be addressed.
Be wary of "All-Band" antennas. While they sound nice, they usually do everything "sorta" well, not the "best", but OK.
Take a good close look at what exactly you want to listen to. Be realistic, then purchase the antenna designed for those frequencies.
Also, do not pay extra for a "digital" antenna. There is no such thing as a digital antenna. Antennas simply catch RF energy, doesn't matter if it's digital or analog, works the same.
Start of by installing the highest grade coaxial cable you can afford. Unless it's a very short run from your antenna to your radio, you'd want to start with something like Times Microwave LMR-400 with the proper connector to match your antenna.
At the radio end, do NOT try to connect LMR-400 directly to your minty fresh scanner. Trying to connect stiff cable like LMR-400 directly to the antenna connector will quickly damage something, usually that minty smelling radio.
Invest in a short jumper from the LMR-400 to the scanner. This should be a lightweight and highly flexible cable with the proper connectors installed. Don't use adapters if you can afford it.
Another good option for coax is to use RG-6. You can find this at Home Depot. While it is a "TV" cable designed for a 75Ω system, it'll work just fine for a scanner.
If you ever plan on getting your amateur radio license, do yourself the favor of getting the LMR-400, it'll be a better choice if you plan on doing any transmitting.
Either way, one of those would work fine.
Lightning protection should be addressed.
Be wary of "All-Band" antennas. While they sound nice, they usually do everything "sorta" well, not the "best", but OK.
Take a good close look at what exactly you want to listen to. Be realistic, then purchase the antenna designed for those frequencies.
Also, do not pay extra for a "digital" antenna. There is no such thing as a digital antenna. Antennas simply catch RF energy, doesn't matter if it's digital or analog, works the same.
SOFA_KING
Member
The answer is simple. A Diamond D130NJ all band discone antenna fed with Andrew hardline! 
Diamond® Antenna ~ D130NJ Super Discone Antenna
Mount it up as high as possible and out in the clear. And if you really want better low band and 6m ham band performance, replace that base loaded coil low band stinger on top with a full 62 3/4" straight whip. Outstanding boost for low band and especially 6 meters.
And LMR400 is lossy compared to good hardline. Way overrated. I'm always amazed at how much further I hear when I switch over to hardline. I like LDF 5-50A (7/8") the best, but use LDF 4-50A (1/2") on runs around 50' or less
Phil.
Diamond® Antenna ~ D130NJ Super Discone Antenna
Mount it up as high as possible and out in the clear. And if you really want better low band and 6m ham band performance, replace that base loaded coil low band stinger on top with a full 62 3/4" straight whip. Outstanding boost for low band and especially 6 meters.
And LMR400 is lossy compared to good hardline. Way overrated. I'm always amazed at how much further I hear when I switch over to hardline. I like LDF 5-50A (7/8") the best, but use LDF 4-50A (1/2") on runs around 50' or less
Phil.
I have one of these up on the roof.. Works great for me on all bands & multiple radios.
WBV-60 Wideband Base Antenna
WBV-60 Wideband Base Antenna
mmckenna
I ♥ Ø
Yeah, Heliax is better but outside the realm of most hobbyists. Running 7/8" through your house gets a bit problematic. Bend radius's and all get to be an issue in a residence.
Don't get me wrong, use the best you can, if you can afford Heliax and you are willing to blow your budget on feedline that measures in the dollar per foot range and $30 connectors, then go for it.
LMR-400 and LMR-600 is decent for the hobbyist. Especially when using a compromise antenna like a discone.
On that note, if the OP isn't really sure what they want to listen to, a discone might be a good choice. Mount it up as high as you can and feed it with the best coax you can reasonably afford and it's a good all around solution.
Don't get me wrong, use the best you can, if you can afford Heliax and you are willing to blow your budget on feedline that measures in the dollar per foot range and $30 connectors, then go for it.
LMR-400 and LMR-600 is decent for the hobbyist. Especially when using a compromise antenna like a discone.
On that note, if the OP isn't really sure what they want to listen to, a discone might be a good choice. Mount it up as high as you can and feed it with the best coax you can reasonably afford and it's a good all around solution.
So should i use the LMR-400 as pig tail are should i run the LMR-400 all the way to the scanner thin use rg-6 are rg-8 as the jumper from the scanner to the LMR-400
mmckenna
I ♥ Ø
I'd run LMR-400, or whatever you can afford from the antenna all the way to your radio. Make the final connection to the radio with something like RG-58.
A foot or two of RG-58 isn't going to insert enough loss to be noticeable and it'll save the connector on the radio from a lot of strain.
I'd recommend LMR-400 or better with male type N connectors on both ends. Order your antenna with a female N connector on it.
Then, simply order a jumper with a female N connector to a BNC male connector to make the final adjustment.
Antenna Farm will sell the LMR-400 (or better if you chose), the antenna with the N connector on it as well as a custom jumper cable with the female N to male BNC connector.
A foot or two of RG-58 isn't going to insert enough loss to be noticeable and it'll save the connector on the radio from a lot of strain.
I'd recommend LMR-400 or better with male type N connectors on both ends. Order your antenna with a female N connector on it.
Then, simply order a jumper with a female N connector to a BNC male connector to make the final adjustment.
Antenna Farm will sell the LMR-400 (or better if you chose), the antenna with the N connector on it as well as a custom jumper cable with the female N to male BNC connector.
VancouverScan
Member
I've been using an Austin Ferret since the late 90's, check them out on line for specs as they are built well and can be purchased from HRO and shipped for free, they cost a bit more than your budget, $259.00. It is a 8' pvc vertical pole that can be placed anywhere easily, it is built to be resonant on all bands. It has an N connection on the antenna.
Coax is important but if you are running a length of 50' or less you can work with just about anything except RG-58.
SOFA_KING
Member
When it comes to antennas and antenna "gain", physics are the limiting factor that can't be overcome by marketing claims and "my antenna is better than yours" claims. People who do radio professionally know this. And although this scanner thing is just a hobby, if what you are asking for is the best reception you can get (within your budget) given the limitations of antenna placement, you need to put together something called a "link budget". This is where you breakdown each component of the antenna system and calculate each gain or loss on the frequencies in question. By properly considering all these pieces of the "link", you can pretty much know what to expect at the end that connects to the radio.
It starts at the antenna. This is the only place you can expect natural "gain". Three factors need to be considered here.
1) Resonance on the frequencie(s) desired. If it has a high return loss (bad VSWR) at any frequency you may want to hear, don't expect good results. Antennas that use coils as part of their design often are narrow band and have dead spots that really degrade frequencies outside the narrow resonance areas they are "tuned" to.
2) Angle of radiation on said frequency or frequencies. This is often where gain is realized by focusing more energy in the angle and direction where you need to RX and maybe TX. This comes at the expense of sacrificing other angles or directions, and this is where size matters and can't be physically overcome by gimmicky marketing claims or "my antenna is the best" claims without reviewing the full specifications at all intended frequencies. For omnidirectional antennas, the only way to get true gain is by stacking multiple elements of dipoles (open, folded, or collinear in design). But then bandwidth is a major limitation and can only work well on frequencies within physical limitations (single band elements). When considering multi-band antennas, be careful to look at all the data concerning frequencies covered without nulls, angles of radiation at all claimed frequencies covered (viewing polar charts of the antenna in question...if the company even published that vital information) , and deceptive gain figures (marketing lies). A small antenna claiming big gain on low frequencies (or worse yet all "bands") is a red flag. If real commercial antennas (the ones we are listening to at tower sites) are 21' tall and have 6 DB of gain, your little 4' antenna can't have anywhere near that gain. It's the law of physics!
3) Height is might. It's mostly about line of site, so height matters to clear obstructions and work out to the curvature of the earth. WARNING: Preamps used as a gain substitute for actual natural physical gain mostly cause major problems with scanners, as they overload the wideband design of the reciver and produce false images. And those are also subject to specifications...like noise figures and overload limitations. The bottom line is you can't expect good results without considering ALL of the physical elements and user requirements. That is the "real deal", and everything else is rubbish.
No matter what you use for feedline, it's a loss. Now the real question is, "how much loss can I tolerate?" Well, considering you just (hopefully) chose the ideal antenna, do you really want to throw away the gains you just made? Probably not! So, you are wise to not use cheap junk feedline as an easy way out, or you'll do just that...throw away perfectly good signals you could have easily received. Feedline is the one area we can usually get hard data of DB loss per foot at given frequency ranges. You can start calculating your losses and might be horrified at the results, especially at the all-so-popular 800 MHz range. This is why pros use hardline and avoid LMR. My LMR use resulted in more noise, which hurt weaker signals, than I ever expected. I use it in only very limited capacity where I can't use hardline...but don't like it. The best way to manage hardline is to terminate it to a weatherproof grounding box just where you want to enter the building. Use something like an Alpha Delta wide-band surge arrestor and ground it well. You get a place to connect smaller feedline for the final run to the scanner, and the all-so-important lightning protection! Then use a high quality, low loss, thin cable like superflex or (my favorite) silver plated / double shielded RG400. Anything like RG58, RG8X or RG6 (not even 50 Ohm cable) will cause a lot more loss than you might think. I've measured it, and was shocked at RG8X. Lost half of my power at UHF even with good connectors installed perfectly. You can't argue with physics and real test data.
Lastly, quality connectors are a must, and need to be installed perfectly. Type N connectors are very low loss, and the professional choice when DIN connectors are too large to consider. That final BNC connection to the radio is unavoidable. Not a bad connector design considering all factors. SMA, as well, is a good small cable connector. Luckily, you can readily purchase most cable and connector types professionally assembled, so you may not need the skills to do your own connector assembly. But it's a skill worth having.
So why, after all this background, do I recommend a Diamond discone? Unless you are ready to combine large single-band omnidirectional gain antennas together into a single feedline, you can't overcome the wideband low-loss design of a QULITY discone antenna. That is why the military uses them extensively. But not all (Voyager's "wet noodle" for example) are a quality design. I have compared discone antennas, and some (like the Comet) are pretty useless. Compared to real commercial gain antennas, they do better that I ever expected for a so-called "unity gain" antenna. The bottom line is I hear a very long distance consistently with modest height. The real gain antennas do a bit better, but only on frequencies they effectively cover. Discone antennas cover just about every frequency my scanner or ham gear need to cover...all in one antenna. By using a 62 3/4" whip on top, I have a wide band 6m and low band extension that I have used to talk to northern New Hampshire and Canada (multiple times...good reports) from my station here in Florida. That is 1400 miles, and if you know the limits of E Skip, that is about as low an angle...and far a distance as you can get on one hop. This proves the focus is low on the horizon and not 35 degrees up in the air. But the best part is this whip also works as a 3/4 wave on VHF high band, so my VHF performance also gets a boost. This antenna blows me away, and not just because I "think" it is the best, or make unsubstantiated claims. The science behind it says it is the practical choice for wide band omnidirectional applications. Made of quality stainless steel, my Diamond discones have lasted over 30 years without any issue. You can't go wrong, especially if you limit all the loss you can in the feedline. Do it right, and you will be rewarded!
Phil
It starts at the antenna. This is the only place you can expect natural "gain". Three factors need to be considered here.
1) Resonance on the frequencie(s) desired. If it has a high return loss (bad VSWR) at any frequency you may want to hear, don't expect good results. Antennas that use coils as part of their design often are narrow band and have dead spots that really degrade frequencies outside the narrow resonance areas they are "tuned" to.
2) Angle of radiation on said frequency or frequencies. This is often where gain is realized by focusing more energy in the angle and direction where you need to RX and maybe TX. This comes at the expense of sacrificing other angles or directions, and this is where size matters and can't be physically overcome by gimmicky marketing claims or "my antenna is the best" claims without reviewing the full specifications at all intended frequencies. For omnidirectional antennas, the only way to get true gain is by stacking multiple elements of dipoles (open, folded, or collinear in design). But then bandwidth is a major limitation and can only work well on frequencies within physical limitations (single band elements). When considering multi-band antennas, be careful to look at all the data concerning frequencies covered without nulls, angles of radiation at all claimed frequencies covered (viewing polar charts of the antenna in question...if the company even published that vital information) , and deceptive gain figures (marketing lies). A small antenna claiming big gain on low frequencies (or worse yet all "bands") is a red flag. If real commercial antennas (the ones we are listening to at tower sites) are 21' tall and have 6 DB of gain, your little 4' antenna can't have anywhere near that gain. It's the law of physics!
3) Height is might. It's mostly about line of site, so height matters to clear obstructions and work out to the curvature of the earth. WARNING: Preamps used as a gain substitute for actual natural physical gain mostly cause major problems with scanners, as they overload the wideband design of the reciver and produce false images. And those are also subject to specifications...like noise figures and overload limitations. The bottom line is you can't expect good results without considering ALL of the physical elements and user requirements. That is the "real deal", and everything else is rubbish.
No matter what you use for feedline, it's a loss. Now the real question is, "how much loss can I tolerate?" Well, considering you just (hopefully) chose the ideal antenna, do you really want to throw away the gains you just made? Probably not! So, you are wise to not use cheap junk feedline as an easy way out, or you'll do just that...throw away perfectly good signals you could have easily received. Feedline is the one area we can usually get hard data of DB loss per foot at given frequency ranges. You can start calculating your losses and might be horrified at the results, especially at the all-so-popular 800 MHz range. This is why pros use hardline and avoid LMR. My LMR use resulted in more noise, which hurt weaker signals, than I ever expected. I use it in only very limited capacity where I can't use hardline...but don't like it. The best way to manage hardline is to terminate it to a weatherproof grounding box just where you want to enter the building. Use something like an Alpha Delta wide-band surge arrestor and ground it well. You get a place to connect smaller feedline for the final run to the scanner, and the all-so-important lightning protection! Then use a high quality, low loss, thin cable like superflex or (my favorite) silver plated / double shielded RG400. Anything like RG58, RG8X or RG6 (not even 50 Ohm cable) will cause a lot more loss than you might think. I've measured it, and was shocked at RG8X. Lost half of my power at UHF even with good connectors installed perfectly. You can't argue with physics and real test data.
Lastly, quality connectors are a must, and need to be installed perfectly. Type N connectors are very low loss, and the professional choice when DIN connectors are too large to consider. That final BNC connection to the radio is unavoidable. Not a bad connector design considering all factors. SMA, as well, is a good small cable connector. Luckily, you can readily purchase most cable and connector types professionally assembled, so you may not need the skills to do your own connector assembly. But it's a skill worth having.
So why, after all this background, do I recommend a Diamond discone? Unless you are ready to combine large single-band omnidirectional gain antennas together into a single feedline, you can't overcome the wideband low-loss design of a QULITY discone antenna. That is why the military uses them extensively. But not all (Voyager's "wet noodle" for example) are a quality design. I have compared discone antennas, and some (like the Comet) are pretty useless. Compared to real commercial gain antennas, they do better that I ever expected for a so-called "unity gain" antenna. The bottom line is I hear a very long distance consistently with modest height. The real gain antennas do a bit better, but only on frequencies they effectively cover. Discone antennas cover just about every frequency my scanner or ham gear need to cover...all in one antenna. By using a 62 3/4" whip on top, I have a wide band 6m and low band extension that I have used to talk to northern New Hampshire and Canada (multiple times...good reports) from my station here in Florida. That is 1400 miles, and if you know the limits of E Skip, that is about as low an angle...and far a distance as you can get on one hop. This proves the focus is low on the horizon and not 35 degrees up in the air. But the best part is this whip also works as a 3/4 wave on VHF high band, so my VHF performance also gets a boost. This antenna blows me away, and not just because I "think" it is the best, or make unsubstantiated claims. The science behind it says it is the practical choice for wide band omnidirectional applications. Made of quality stainless steel, my Diamond discones have lasted over 30 years without any issue. You can't go wrong, especially if you limit all the loss you can in the feedline. Do it right, and you will be rewarded!
Phil
Last edited:
Nice post. A few observations:
1. The military likely uses Discones due to the size and bandwidth. They are resonant nearly everywhere which is what they need. They can also be broken down to a very small package.
2. In my wet noodle comment, that applies to all three manufacturers of Discones I tried. Radio Shack, Diamond, and a third one I don't recall. All three were outperformed by a stock rubber duck about 15-20 feet below them. My recommendation would be the ST-2 which runs rings around the Discone design. Unfortunately, they are currently not in production. In general, the larger the antenna, the more capture area you will have and the better the reception will be. While this is not an absolute, it explains why the ST-2 picks up so much better than the Discone.
3. The BNC connector is a very high quality connector not too far behind the N connector for the same reasons - the design minimizes the impedance bump typical of other connectors. While the N has some other advantages, the BNC is a very good choice and is not the proverbial straw that could have been inferred.
1. The military likely uses Discones due to the size and bandwidth. They are resonant nearly everywhere which is what they need. They can also be broken down to a very small package.
2. In my wet noodle comment, that applies to all three manufacturers of Discones I tried. Radio Shack, Diamond, and a third one I don't recall. All three were outperformed by a stock rubber duck about 15-20 feet below them. My recommendation would be the ST-2 which runs rings around the Discone design. Unfortunately, they are currently not in production. In general, the larger the antenna, the more capture area you will have and the better the reception will be. While this is not an absolute, it explains why the ST-2 picks up so much better than the Discone.
3. The BNC connector is a very high quality connector not too far behind the N connector for the same reasons - the design minimizes the impedance bump typical of other connectors. While the N has some other advantages, the BNC is a very good choice and is not the proverbial straw that could have been inferred.
I'll add that you need to consider where your antenna will be located, relative to what you want to hear. A discone can be a great choice if you want to hear stuff from all directions. However, it might make hearing a trunked simulcast system worse, especially if you happen to be located between several towers in the system. In that case, a yagi or directional antenna will likely work better.
Just as another data point, I've used both an ST-2 and a Diamond discone. These were mounted on the same pole, at the same height, at different times. Discone was fed with 50' of LMR-400 UltraFlex, the ST-2 with RG6. For weak, distant stations I noticed very little difference between the two on VHF-Hi, and UHF Public Safety bands. I did notice some improvement at 860 MHz with the ST-2, which is why it has taken the place of my discone. I've never seen any official gain specs for the ST-2, but I doubt it's much better than unity on any given band. I'm NOT knocking the ST-2. I think it was a great value when it was available, and wish it still were. But for me it never made my discone seem inferior. In fact, I liked that you could transmit with the discone on 2M/440, as well as use it as a scanner antenna, a trick the ST-2 can't do.
.
I'll throw out another antenna recommendation, the DPD Omni-X:
DPD Productions - Scanner, Aviation, NOAA, Low-Band, 700 MHz Public Safety, Base & Mobile Radio Antennas for Commercial & Hobbyist Applications
It's a competent wide band receive antenna, on par with a discone in my experience, but a bit more stealthy. Its not cheap, but not terribly expensive either. It's well made (in the USA no less), sturdy, and can likely hold up to wind storms better than some of its competition, as it is fairly short and compact. It's not good for VHF-Lo, so if that's important you'd need to look elsewhere.
.
DPD Productions - Scanner, Aviation, NOAA, Low-Band, 700 MHz Public Safety, Base & Mobile Radio Antennas for Commercial & Hobbyist Applications
It's a competent wide band receive antenna, on par with a discone in my experience, but a bit more stealthy. Its not cheap, but not terribly expensive either. It's well made (in the USA no less), sturdy, and can likely hold up to wind storms better than some of its competition, as it is fairly short and compact. It's not good for VHF-Lo, so if that's important you'd need to look elsewhere.
.
I've got a similar setup, only the Discone is top mounted on a pole and the ST-2 is side mounted just below it (top of the ST-2 is a bit below the cone elements). The Discone picks up 2 or 3 weather channels while the ST-2 picks up 5 or 6.
I wonder if you had a bad balun. Or maybe you are in a dense RF area where the improvement was not realized.
Just based on physics it should have at least 5.5 to 6 dB gain at VHF High (5/8 wave dipole at 3 dB plus two quarter wave dipoles which combined would be close to 3 more dB). It may well be Unity (or close to it) on VHF Low Band.
There could be a balun issue, but the ST-2's performance is actually very good, so I have no reason to suspect the balun. It's just not significantly better performance than the discone. I am in a dense RF area, but I'm using $500 worth of Par notch filters to mitigate that problem, the same filters I used for the discone. Both antennas are excellent on VHF-Hi Public Safety. I routinely get decent, copyable analog signals on stations that are 50 to 70 miles distant, which is all that is reasonable to expect, so I have no complaints with either antenna. Much beyond that range it won't matter how great the antenna, or coax, or receiver, as you're bumping up against the pure physics of VHF propagation, unless of course you get some help from tropospheric ducting.
Well, you'd think if the ST-2 actually had that much gain that Antenna Craft would have touted it proudly. Instead we get a spec sheet that looks like this:
.
Attachments
Blackswan73
Active Member
An antenna that is often overlooked, probably because of being associated with CB, is Firestik. Firestiks are US made, and very weather resistant, due to their vinyl coated fiberglass construction. I currently use a 2m Firestik, and a mobile scanner Firestik. Firestik also makes a base scanner model as well. Firestik scanner antennas are discontinued, but still can be found. The base scanner antenna was simply a mobile scanned antenna with an artificial ground plane. If you need to, you can fabricate a ground plane and use the three foot or four foot mobile scanner antenna
Last edited by a moderator:
- Status
Similar threads
